Room air conditioner filter system



Sept. 18, 1956 R. J. CALLAN ETAL ROOM AIR CONDITIONER FILTER SYSTEM 2 Sheets-Sheet 1 Filed March 10, 1954 iii-W ix p 8, 1956 R. J. CALLAN ETAL ROOM AIR CONDITIONER FILTER SYSTEM 2 SheetsSheet 2 Filed March 10, 1954 aaww, 7;- NW 1%,

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w'mzy United States Patent ROOM AIR CONDITIONER FILTER SYSTEM Robert J. 'Callan, Alfton, and Ta-Hsien Kuo, St. Louis, Mo., assignors to Magic Chef, Iuc., St. Louis, Mo., a corporation of New Jersey Application March 10, 1954, Serial No. 415,204

8 Claims. (Cl. 62- 129) This invention relates to air filter systems, and more particularly to an air filter system for a room air conditioner.

Among the several objects of the invention may be noted the provision of an improved air filter system for a device such as a room air conditioner which makes it easy and economical to change filters; the provision of a filter system which makes it easy to determine when filter changing is needed; the provision of filter system utilizing a roll of filter material, from which a fresh length of material may be readily pulled into filtering position when it is desired to change filters, the used portion of the material being readily cut off for disposal; and the provision of a system of this class which also provides for ready replacement of the roll of filter material. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a view in perspective of the interior cabinet of a room air conditioner having an air filter system of this invention, part of the cabinet being broken away to show interior details;

Fig. 2 is an enlarged vertical cross section taken on line 2-2 of Fig. 1, broken away at the center; and,

Fig. 3 is an exploded view illustrating the assembly of certain-parts of the system, a roll of filter material being shown in phantom.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, there is indicated at 1 the interior housing or cabinet of a room air conditioner. The cabinet 1 encloses the usual evaporator 3. The evaporator 3 is conventionally mounted on a base along with other conventional air conditioner components such as a blower, a compressor, etc. (not shown). It will be understood that the base is mounted in a window on the window sill. The cabinet 1 is removable from the base (and from the evaporator 3). It has a row of lower air intake openings 5 in its front, and a row of upper air grilles 7 in its front for directional discharge of air into the room. The top of the cabinet is spaced above the top of the evaporator and the front of the cabinet is spaced from the front of the evaporator. While the blower is not shown herein, it will be understood that it is located on the outside of the evaporator 3 and draws air from the room through the air intake openings 5 and through the evaporator (where the air is cooled) and discharges the cooled air through the grilles 7. Air discharged by the blower flows to the grilles 7 through a passage 9 (see Fig. 2) between the top of the evaporator and the top of the cabinet 1 and through a passage 11 defined by the top of the cabinet in conjunction with a panel 13 which extends forward from the top of the evaporator. The cabinet has a bottom opening 15 in front of the front or intake side of the evaporator.

In accordance with this invention, a holder 17 for a roll R of filter cloth C is mounted at the top of the space defined by the front of the evaporator, the front of the cabinet and the panel 13. As shown, the holder 17 is made of a length of stiff wire having end portions bent to provide roll-holding loops 19 at the ends of a straight bar portion 21 of the Wire. The loops lie in planes at right angles to the length of bar 21 and include straight initial portions 23 which angle downward and outward from the ends of bar.21 and straight return portions 24 which terminate short of portions 23, to provide openings 25 for passage. of the filter cloth over the bar 21, the latter serving as a guide for the cloth. Return portions 24 have upwardly extending projections 27 at their ends receivable in holes 29 in the panel 13. Removable fasteners such as spring clips 31 are applied to projections 27 after their upward insertion in holes 29 to secure the holder to the bottomof panel 13.

The filter cloth C may be made, for example, of plasticbonded glass fibers, and is thin enough to be Wound up in a roll and to be readily unrolled and cut with a scissors. Its width is somewhat greater than the width of the evaporator 3. For locating and holding the roll R in lateral alignment with the intake side of the evaporator 3, there is provided a guide 33 consisting of a narrow plate 35 having a length corresponding to the width of the cloth (the length of the roll) provided with downwardly extending end flanges 37 and a downwardly extending back flange 39. The plate 35, which in the assembly engages the bottom of panel 13, has holes 40 receiving the projections 27, these holes being located so that end flanges 37 are positioned at opposite sides of the evaporator 3. Flanges 37 are engageable by the ends of the roll R to preclude axial shifting of the roll. Back flange 39 engages the evaporator 3 along the upper portion of the front of the evaporator. l The filter cloth C unrolled from the roll R extends through the loop openings 25 and over the guide bar 21, and down between the bar 21 and the back flange 39 of guide 33 on the front or intake side of the evaporator 3, reaching to the bottom thereof. For retaining the filter cloth. against the intake side of the evaporator, there is provided an open spring frame 41. This is shown as being made of a length of stiff wire bent to U-shape and having its ends bent as indicated at 43 and welded to the straight reaches 23 of the loops 19 of the roll holder 17. The U-shaped frame 41 extends downward from the roll holder 17, the lower cross-bar 45 of the U being located somewhat above the bottom of the evaporator 3. The frame is inherently springy, and presses the cloth against the front of the evaporator without substantially obstructing the flow of air. The cross-bar 45 of the frame has an outwardly projecting central loop 47 for insertion of a finger between the front of the evaporator and the cross-bar to spring the frame away from the evaporator. To prevent the cloth from being drawn into the spaces between the fins of the evaporator, a grid 49 is secured in position on the front of the evaporator. As shown, the grid consists of horizontal wires 51 welded to a vertical wire 53, the horizontal wires having rearwardly bent ends 55 received in holes 57 in flanges 59 at the sides and coplanar with the front of the evaporator.

From the above, it will be seen that air drawn by the blower (not shown) through the air intake openings 5 (and also any air drawn through the bottom opening 15 of the interior cabinet 1) flows through the length of filter cloth covering the front of the evaporator 3 for filtration before it passes through the coil and is discharged back into the room. While the cloth is relatively thin as compared rigid-frame single-use filters of the type heretofore conventionally used in air conditioners, it is no less effective for filtration. This is because practically all dust, lint, pollen and other foreign particles is collected at thefsurfa'ce rather than interiorly of a filter, and a thin filter is practically equally effective for air filtration as a thick filter.

The condition of the length of filter cloth in front of the evaporator may be inspected through thefair intake openings 5, Which'are relatively large for this purpose. In this respect, it may be observed that the filter cloth is of neat appearance and appears as a cloth panel in the rear of the intake openings. When the length of cloth extending down across the front of the evaporator is observed to be dirty, the springfrarne '41 may be sprung away from the cloth by reachingin through the bottom opening 15 of the cabinet 1, and inserting the finger in the loop 47 to pull the lower. end of the frame toward the front of the cabinet, and then a fresh length of the cloth may be pulled down from the roll of cloth to extend in front of thev evaporator. dirty length of cloth then hanging down below the bottom of the cabinet 1 may be cut off with a scissors and thrown away. The cloth may be suitably marked to indicate where it should be cut.

The roll R may contain a sufficient length of cloth for five filter changes, for example. The last filter length of the cloth may be so labelled to serve as a reminder that a new filter roll should be ordered. To insert a fresh roll R in the holder 17, the cabinet 1 is removed, clips 31 are unfastened from projections 27, and the entire holder (including the'spring frame 41) is removed. The guide 33 is separated from the holder, and the fresh rollinserted endwise through the loops 19. The first filter length is pulled from the roll and trained over the bar 21, then guide 33 is applied and the assembly returned to its position under the panel 13.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the. accompanying drawing'sshall be interpreted. as illustrative and not in a limitingsense.

' Welclaim:

l. A room air conditioner comprising a base, an evaporator on the base, and'a'r'emovable cabinet enclosing the evaporator, said cabinet having a lower opening in front of the evaporator, the top o-f the cabinet being spaced above the top 'of the'evaporator and the front of the cabinet being spaced from the front of the evaporator, the cabinet having an upper air outlet, air being drawn through the evaporator from its front and flowing to the outlet over the top of the, evaporator and through a passage beneath the top of the cabinet, a roll holder mounted at the top of the space between the front of the evaporator and the front of the cabinet for holding a roll of filter material with its axis generally horizontal and generally parallel to the front of the evaporator, and a guide for the filter material extending horizontally across the front of the evaporator closely adjacent the top of the evaporator, whereby a length of material extending from the roll may be trained over the guide to pass into filtering position down across the front of the evaporator to said lower opening for filtering air drawn through the evaporator, the end of the material being accessible through said lower opening for pulling it out of the cabinet to draw a fresh length of the material into filtering position.

2. A room air conditioner comprising a base, an evaporator on the base, and a removable cabinet enclosing the evaporator, said cabinet having a bottom opening in front .of ,the evaporator, thetop. of the cabinet being spaced above the top of the evaporator and the front of the cabinet being spaced from the front of the evaporator, the cabinet having an upper air outlet, air being drawn through the evaporator from its front and flowing to the outlet over the top of the evaporator and through a passage defined by the top of the cabinet and a panel extending forward from the top of the evaporator to the front of the cabinet, a roll holder removably attached to the bottom of said panel for holding a roll of filter material with its axis generally horizontal and parallel to the front of the evaporator and at the top of the space defined by the front of the evaporator, the front of the cabinet and said panel, said roll holder including a guide for the filter material extending horizontally across the front of the evaporator adjacent the top of the evaporator under the panel, whereby a length of material extending from the roll may be trained over the guide to reach in filtering position down across the front of the evaporator to said bottom opening for filtering air drawn through the evaporator, and releasable means accessible through said bottom opening adapted to press said length of material against the front of the evaporator Without substantially obstructing the How of air, the end ofthe material being accessible through said bottom opening for pulling it out of the cabinet upon releasing said means to draw a fresh length of the material into filtering position.

3. A room air conditioner comprising a base, an evaporator on the base, and a removable cabinet enclosing the evaporator, said cabinet having a bottom opening 121 front of the evaporator, the top of the cabinet being spaced above the top of the evaporator and the front of the cabinet being spaced from the front of the evaporator, the cabinet having a lower front air intake and an upper front air outlet, air being drawn from the illtake through the evaporator from its front and flowing to the outlet over the top of the evaporator and through a passage defined by the top of the cabinet and a panel extending forward from the top of the evaporator to the front of the cabinet, a roll holder removably attached to the bottom of said panel for holding a roll of filter material with its axis generally horizontal and parallel to the front of the evaporator and at the top of the space defined by the front of the evaporator, the front of the cabinet and said panel, said roll holder including a guide for the filter material extending horizontally across the front of the evaporator closely adjacent the top of the evaporator under the panel, whereby a length of material extending from the roll may be trained over the guide to reach in filtering position down across the front of the evaporator to said bottom opening for filtering air drawn through the evaporator, and spring means carried by and extending down from the roll holder for pressing said length of material. against the front of the evaporator, the lower end of said spring means being accessible through said bottom opening for springing it away from the front of the evaporator to release the material, and the end of the material being accessible through said bottom opening for pulling it out of the cabinet upon releasing said spring means to draw a fresh length of the material into filtering position.

4. A room air conditioner as set forth in claim 3, said roll holder and guide consisting of a length of stiff wire having a straight portion constituting said guide, and roll-holding loops at its ends, said loops terminating in upwardly extending projections received in holes in said panel, with fasteners removably attached to the portions of the projections extending above the panel.

5. A room air conditioner as set forth in claim 4, the spring means consisting of a U-shaped spring wire frame, the upper ends of the sides of the U being secured to the loops.

6. A room air conditioner as set forth in claim 5, the lower portion of the U having an outwardly projecting loop for reception of a fingerto springthe frame away from the front of the evaporator.

upwardly extending projections received in holes in said 5 panel, with fasteners removably attached to the portions of the projections extending above the panel, and means associated with the roll holder for locating and holding the roll of filter material in lateral alignment with the evaporator.

8. A room air conditioner as set forth in claim 7, said roll locating and holding means comprising a plate disposed between the roll holder and the bottom of the panel having holes receiving said projections and downwardly extending end flanges engageable by the ends of the roll.

References Cited in the file of this patent UNITED STATES PATENTS 915,616 Mackintosh Mar. 16, 1909 10 2,040,758 Naugler May 12, 1936 2,119,978 Wolthuis et al. June 7, 1938 2,299,527 Cody Oct. 20, 1942 

